Jwaneng is owned by Debswana, and the mine was opened in 1982. It now produces 60 per cent to 70 per cent of Debswana’s total earnings. De Beers claims Jwaneng is the richest mine in the world. In 2009, the mine treated 8.2 million metric tonnes of rock to produce 11.5 million carats.

Orapa is another Debswana-owned mine. The mine was opened in 1971 and is an open-pit mine from which nearly 13 million metric tonnes of rock was processed in 2010, or about one metric tonne for every 1.3 carats.

The Orapa mine produced 9.53 million carats in 2010.Image: A diamond ring.Photographs: Tyrone Siu/Reuters

Rio Tinto owns 60 per cent interest in Diavik and is the mine’s operator.

The mine went into production in 2003 as an open-pit operation that will be transitioned to a fully underground mine by next year.

The kimberlite deposits are small, but produce high-grade gem quality stones. The Diavik mine produced 6.5 million carats in 2010..Image: A model displays the Sun-Drop diamond during a media preview in Geneva.